1. Field of the Invention
This invention is in the field of lighting control circuits and methods therefore and, more particularly, relates to touch control circuits for ornamental lamps and methods therefore.
2. Description of the Prior Art
Touch control of one or more lamps is typically implemented with a multistate circuit that alters the firing angle of a silicon controlled rectifier. The silicon controlled rectifier is connected in series with the lamps and an AC power source.
The circuit usually includes a capacitor formed by ground and a control element. The capacitor has a value that is altered in response to a person touching the control element. Hence, an initial touch of the control element may, for example, cause the circuit to make a transition from an initial state to a first state. A subsequent touch of the control element causes a transition from the first state to a second state. Transitions to other states may be caused in a similar manner. After a known number of transitions, the circuit is in its initial state.
Since the silicon controlled rectifier has a firing angle that is altered by changing the state of the circuit, the average current through the silicon controlled rectifier is related to the state of the circuit. Therefore, the intensity of light is related to the state of the circuit.
The above described circuit and other touch control circuits of the prior art are implemented in a manner that is complex, expensive, unreliable and unsuited for controlling ornamental lamps, such as those used for lighting a christmas tree. The application and removal of power to christmas tree lamps often requires a person to crawl under the tree to reach an electrical outlet. This often results in needles and ornaments falling off the tree creating a disorderly atmosphere and a possible safety hazard. Hence, there was a need for a simplified circuit for touch control of christmas tree lamps.